[填空题]
A stone is dropped frnf8fgx8qc(-h:u*gslcf2 z m7 om the top ofxgmmjvg z:kd1) * ejt3;wb6q r04 lug )zr2q;c a cliff. The splash it makes when striking the water below is heard 3.5 s later. Howmk3t;vb: uxj)1 gg*qwdg;r0m4 qj)r l6 zc2ze high is the cliff? m